The only way you would not know that I am British is if you:
a) have never been to this website before today,
b) have been here before but understandably don’t read any of the words I write, or
c) know so little about vexillology that you didn’t even realise that the site’s logo had a flag in it.
Because of my nationality – English rather than British, but we’ll worry about that later – it is inevitable …